Technical Field:
The disclosure concerns a chamber for processing a workpiece, and a method of monitoring conditions inside the chamber with multiple sensors linked to a process controller by radio frequency (RF) communication channels.
Background Discussion:
A reactor chamber for processing a workpiece is typically vacuum-sealed during processing. A process controller external of the chamber controls process parameters, such as gas flow rates, plasma source power level, heater currents, electrostatic chucking voltage, vacuum pumping rate, coolant flow rate, as some examples. Process conditions are difficult to ascertain, generally because the sensors must be located so as to be accessible to signal-carrying wires while not interfering with plasma processing. As a result, during processing, there may be little or no sensing of internal chamber conditions communicated to the process controller. This prevents real time feedback control of chamber conditions by the process controller.